NASA's Science Mission Directorate (SMD) intends to release a Draft Announcement of Opportunity (AO) in June 2009 for Discovery Program missions. The Discovery Program conducts Principal Investigator (PI)-led space science investigations in SMD's planetary programs under a not-to-exceed cost cap. It is anticipated that approximately two to three Discovery investigations will be selected for 9-month Phase A concept studies through this AO. At the conclusion of these concept studies, it is planned that one Discovery investigation will be selected to continue into Phase B and subsequent mission phases. There will be no Missions of Opportunity (MO) solicited as part of this AO. All MO are now solicited through the Stand Alone Mission of Opportunity Notice (SALMON) AO.
Full notice below